1. Pulmonary/Critical Care Medicine Service, Walter Reed Army Medical Center, Washington, DC 20307-5001
2. Infectious Disease Service, Brooke Army Medical Center, Fort Sam Houston, TX 78231
3. Department of Medicine, Walter Reed Army Medical Center, Washington, DC 20307-5001
4. Department of Transfusion Medicine, National Institutes of Health, Bethesda, MD 20892-1184